1. Technical Field
The present disclosure relates to the field of terahertz imagers, and in particular to a terahertz imager and method including a reset function.
2. Discussion of the Related Art
A terahertz (THz) imager is an image sensor adapted to capture an image of a scene based on waves in the terahertz frequency range. In general, terahertz waves are considered to comprise waves having a frequency of between 300 GHz and 3 THz. These frequencies, for example, correspond to wavelengths of one millimeter or less. For example, a 1 THz wave has a wavelength of approximately 300 μm.
Terahertz imagers are used widely for applications in which it is desirable to “see through” certain materials. In particular, terahertz waves have good penetrability in many dielectric materials and non-polar liquids. They are however almost entirely reflected by metals and absorbed by water molecules. This makes terahertz imagers particularly suited for applications such as in the security scanners used at airports and in devices used to analyze works of art. The wavelength is in general short enough to achieve good spectral resolution for imaging, but long enough such that the waves are scattered relatively little by air particles such as dust or smoke.
Due in part to a high frequency of the terahertz signal, and also to the relatively small signal strength that should be captured by the terahertz imager, there is generally a need in the art to improve the image quality of terahertz imagers.